388 JOURNAL OF ECONOMIC ENTOl\WLOGY [Vol. 13 portant is necessary to the most successful control of this . In addition to this I am convinced that all of the· apple trees liable to infestation in an orchard should be sprayed in order to prevent any migration of the flies from untreated varieties. In any clean-up attempt all old derelict trees about the farm buildings should be thoroughly sprayed or else cut down and destroyed.

WILD HAWTHORNS AS HOSTS OF APPLE, PEAR AND QUINCE PESTS

By WALTER H. WELLHOUSE, Ithaca, N. Y. Downloaded from The wild hawthorn trees have for many years been recognized by entomologists as the native hosts of a number of injurious native in- sects which now attack the apple, pear and quince, having adopted these hosts after they were introduced and cultivated in North Amer- ica. Among the number may be mentioned the apple maggot, Rhago- http://jee.oxfordjournals.org/ letis pomonella, the dark apple red bug, H eterocordylu8 malinus, the quince curculio, Conotrachelus cratcegi, the lesser apple worm, Las- peyresia prunivora and the woolly apple aphis, Eriosoma lanigera. This migration to new hosts has been generally attributed to the close botanical relationship which exists between the hawthorns and the apple, pear and quince, all four being classed in the apple family. Another factor which tends to make these hosts interchangeable is by guest on June 7, 2016 their almost identical habitat. This allows which are re- stricted by differences in temperature, moisture, light or soil, as well as by botanical relationship, to accept apple in place of hawthorn. The native hawthorns grow wild in most of the apple and pear growing sections of the country. The planting of orchards in places where hawthorns were growing has already initiated a number of new fruit tree pests. With the continued extension of agriculture the uncul- tivated areas where hawthorns grow are still being reduced and their insect population must continue to seck substitute hosts. The writer has a list of 374 species of insects which have been found to feed upon the hawthorns, and 210 of the species are found in the United States. Very few of these seem to be permanently injurious to the hawthorns and many of them do almost no injury, yet when they adopt as a host the apple, pear or quince which has been nursed and shielded from hardships so long that it has become tender and non- resistant, the injury may become much greater. For instance the puncture of the quince curculio in the side of a haw causes no great deformation of the fruit but its puncture in the side of a quince or pear will cause a marked depression and result in a knotty fruit. October, '201 WELLHOUSE: HAWTHORNE INSECTS 389

Among the more important of the species which arc now only Cra- tregus or hawthorn pests but which we may probably expect on our ~ultivated fruits later arc the following: The hawthorn blossom weevil, Anthonomus nebulosus Lee. Its life history and habits are identical with those of the apple blossom weevil of Europe which, according to Theobald, sometimes destroys 40 pel' cent of the apple crop in England. As yet our species attacks only Cratregus but its habit of attacking the fruit buds would make it a very dangerous pest if it should attack the apple. The hawthorn fruit miner, Blastodacna curvilineella Chamb. The larvre of this little Cosmopterygid are among the most common causes of "wormy" haws in Central and they probably are dis- Downloaded from tributed at least over the eastern states. The larvre have the habit of leaving the fruit in early autumn and burrowing into a dead twig or weed stem to spend the winter. They have undoubtedly been long overlooked because they are very active and work their way through the breeding cages to escape even through several layers of fine meshed http://jee.oxfordjournals.org/ cheese cloth. A new leaf bug, Lygus univittatus Knight, resembling the false tarnished plant bug in appearance, has been found by the writer punc- turing the fruits of Cratregus at Ithaca and Knight believes this will eventually become an apple pest. Its punctures do not deform the haws to any extent but may affect the apple differently. A number of leaf-hoppers, the most numerous of which are Empoa by guest on June 7, 2016 querci, Lamenia vulgaris, Erythroneura obliqua, and Idiocerus provan- cheri, cause considerable damage to the Cratregus foliage. The four-spotted hawthorn aphid, Macrosiphum cratcegi Monell, remains all summer on hawthorn and has caused much damage to the trees even durin!!; warm dry weather. It is easily distinguished from our eOlnmon hawthorn and apple aphids by the four conspicuous dark green spots arranged in a rectangle on the backs of the apterous females. oreasella Clem. A little white and gold bud which in the larval stage bores into the terminal buds causing them to wilt and die in :\I.ay. The blackened terminals are occasionally very nu- merous on hawthorns about Ithaca. Over 100 species of insects which feed on apple also feed on haw- thorns. Among them are the following common apple pests:

False tarnished plant bu!/:,LY(Jus communis Apple aphids (Aphis ave1UP,A. pomi, A. sorbi, Eriosoma lanigera) Scale insects (Aspidiotus perniciosus, Chiunaspis furfura, Lepidosaphes ulmi, Lecaniwn corni, etc.) Flea beetles (lIalticafoliacea Lee., Crepidodera helxines Linn., etc.) 390 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 13

Apple curculio, Anthonomus quadrigibbus Plum curculio, Conotrachelus nemtphar Apple weevil, Pseu,danthonomu,s cratregi Hickory tussock moth, H alisidota caryre White marked tussock moth, Hemerocampa leltCOstigma Antique tussock moth, N otolophus antiqua Yellow-necked apple caterpillar, Datana ministra Red-humped apple caterpillar, Schizu,ra concinna Tent-caterpillars, Malacosoma americana, M. disstria Fall webworm, Hyphantria eunea Leopard moth, Zeuzera pyrina Canker-worms, Alsophila pometaria, Paleaerita vernata Bud , Tmetoeera oeellana, Reeurvaria nanella

Leaf rollers, Arehips argyrospila, A. rosaeeana, Ancylis nubeeulana, Eulia quad- Downloaded from rifaseiana Lesser apple worm, Laspeyresia prunivora Case bearers, Coleophora jleteherella, C. malivorella Leaf miners, Tischeria malifoliella, Ornix geminatella Leaf crumpler, Mineola indigenella

Apple maggot, Rhagoletis pomonella http://jee.oxfordjournals.org/ The popular belief that the round-headed apple-tree borer, Sap erda candida, and the codling moth, C1fdia pomonella, are common feeders on Cratregus has not been borne out by the writer's observations. In a number of natural thickets where hawthorns and seedling apple grow together the round-headed borers have been watched for two years. The adults were quite commonly found resting on the foliage of both

hawthorn and apple in June and July but the larvre could be found only by guest on June 7, 2016 in the apple. The apple was so heavily infested that very few trunks remained standing and many young sprouts from the roots had grown up in their places. The larvre were found girdling these sprouts and were also infesting a well kept orelaI'd across the railroad track. The hawthorns showed no sign of h~ving been touched by the borers. At least two of our common sp, )S of hawthorns, Cratregus punctata and C. pruinosa were present in th, se thickets. The codling moth ha£ not been found among the insects reared from the haws during the past two seasons and only one record has been found of its ever being reared from hawthorn. That is in the notes of the late Professor Slingerland. He states that in September 1890 "I gathered a lot of haws and placed them in cages to breed the cod- ling moth. Examined several (25 perhaps) of the haws and never failed to find at least one larva in each. May 13 one adult emerged. Several other smaller moths were found in the cages also. May 19 one adult emerged and is pinned." The smaller moths were probably the lesser apple worm, Laspeyresia prunivora, since this species has been reared in abundance from the haws. The larvre of L. prunivora have undoubtedly been mistaken for those of the codling moth in October, '201 PETERSON: ORIENTAL PEACH MOTH 391

many cases and since their resemblance is very close it is not surprising that the codling moth was believed to breed quite commonly in haws. In view of the fact that the wild hawthorns are hosts of many of our present apple, pear and quince pests and also of many potential insect pests, not to mention the cankers, blights and rusts which they may harbor, should we not remove them from the vicinity of our orchards or at least give them insecticidal treatment? The cumulative benefit which would be gained from spraying an orchard several years in suc- cession may be lost if the surrounding country continually furnishes a new supply of pests. Downloaded from SOME STUDIES ON THE EFFECT OF ARSENICAL AND OTHER INSECTICIDES ON THE LARVlE OF THE ORIENTAL PEACH MOTH

By ALVAH PETERSON, Assistant Entomologist, New Jersey Agricultural

Experiment Station http://jee.oxfordjournals.org/

INTRODUCTION The oriental peach moth, Laspeyresia molesta Busck is found in several localities in New Jersey. It is particularly abundant in orchards about Red Bank and New Brunswick. The author has given this pest considerable attention for two seasons, 1918 and 1919. During these seasons it has been noted that there have been at least three full broods and a partial fourth. The first larval injury to the by guest on June 7, 2016 twigs in 1919 was seen the first week in June at Mr. J. C. Hendrick- son's three year old peach orchard (Hale variety) near Middletown, N. J., at that time no tree possessed over ten injured twigs. In 1918 this orchard was severely infested. fme of the trees had over 90 per cent of the twigs injured during the >nth of July. During 1919 the infestation in this orchard was app: oximately 50 per cent less than in 1918. The last fresWy injured twig observed in 1919 was found on August 30 in the orchard at the college farm. Twill;injury to peach trees is most severe during the first three years after the trees are set out in the orchard. It has been repeatedly observed that in old orchards (five years or more) twig injury is not serious. Several old orchards have been examined which are adjacent to heavily infested young orchards and little or no twig injury could be found. It is apparent that the larvre prefer young, tender, vigorously growing shoots. The first fruit injury in 1919 was seen the last week in June while the last fruit infestation was observed on September 10 at New Brunswick. So far as known, no fresh larval injury of any description has been seen